Automatic separating mechanism of a copying machine

ABSTRACT

A separating mechanism in a photocopying machine separates a traveling stack of a negative and a positive sheet upon exposure of the latter by light beams passed through the former before reaching a developing section of the copying machine by passing the stack through a pair of differential feed rollers and subsequently deflecting that lead sheet to cause separation.

United States Patent Koguchi et al. Aug. 29, 1972 [54] AUTOMATIC SEPARATING [56] References Cited MECHANISM OF A COPYING MACHINE UNITED STATES PATENTS [72] Inventors: Masami Koguchi; Isao Takahashi, 3,448,980 1969 Yanagawa /6 MA Tokyo, both of Japan 3,493,227 2/1970 Yanagawa ..271/64 MA 3,591,286 7/1971 Yanagawa ..355/106 [73] Assignee: Bunshodo Co.,Ltd.,Toky0,Japan Primary Examiner-Sarnuel S. Matthews [22] Flled' 1971 Assistant ExaminerRichard M. Sheer PP 201,770 Attorney-Richard C. Sughrue et al.

[30] Foreign Application Priority Data ABSTRACT Nov. 24, 1970 Japan ..45/103560 A Separating mechanism in a p py machine separates a traveling stack of a negative and a positive [52 US. Cl. ..355/106, 355/110, 271/64 MA sheet p exposure of the latter y light beams [51] Int. Cl. ..G03b 27/30 passed t g t former before r hing a d v l p- [58] Field of Search ..355/ 104, 106, 108, 110, 10; ing section of the copying machine by passing the 95/89 L; 271/64 MA stack through a pair of differential feed rollers and subsequently deflecting that lead sheet to cause separation.

1 Claim, 6 Drawing Figures XL hill AUTOMATIC SEPARATING MECHANISM OF A COPYING MACHINE has been passed through the developing bath; or alternatively, it comprises the above kind of liquid container vessel, and a liquid applicator roll partially immersed in the developing bath.

In the conventional machine of the above kind, the stack of the negative and positive sheets jointly introduced into the machine and jointly exposed to light therein will tend to advance in its jointly overlapped state further towards the developing section. Therefore, a manual separating job must normally be performed so as to separate the both sheets from each other before arrival at the developing section, so as to take out the negative from the stack. Such additional manual job is naturally troublesome and time consuming, especially when a large number of photo-prints must be prepared by the machine.

For avoiding such conventional drawback, there have been raised various prior proposals which provide, however, substantially complicated mechanisms, in spite of their insufficient and defective separating function.

It is therefore the main object of the invention to provide an efficient and reliable automatic separating mechanism of the above kind, capable of obviating the prior drawback, and indeed, with use of a highly simplified structure of the mechanism.

This and further objects, features and advantages of the invention will become more apparent when read the following detailed description of the invention by reference to the accompany drawings, in which:

FIG. 1 is a schematic elevational section of a preferable embodiment of a photo-copying machine embodying the automatic separating mechanism according to this invention.

FIG. 2 is a detailed and enlarged sectional view of a part of the photo-copying machine shown in FIG. 1.

FIG. 3 is an illustrative enlarged schematic view of a part of FIG. 1, for the illustration of the essential function of several important constituents of the photocopying machine shown therein.

FIG. 4, (1)(4) is illustrative of a series of operational steps of the mechanism substantially shown in FIG. 3.

FIGS. 5 and 6 are similar views to FIG. 3, illustrating, however, two different modifications thereof.

Referring now to the drawings, numeral 1 represents generally a box-type casing of l a photo-copying machine which comprises a developing section 2 and an exposure section 3.

The exposure section 3 comprising a transparent drum 4 made preferably of glass, transparent plastic or the like material. This drum 4 is opened at both ends and a pair of elongated cylindrical fluorescent discharge tubes 21 and 22 are provided within the scope of the interior space of the rotatable drum 4. These tubes 21 and 22 are mounted at their both ends in respective sockets 21a and 22a which are fixedly mounted on the front and rear panels, not shown of the casing 1. These tubes are connected naturally through proper leads and main switch means to a current source, although not specifically shown on account of. their popularity. These tubes 21 and 22 serve naturally as the light source for the exposure purpose as conventionally.

An endless belt 23 is threaded around the drum 4, a series of separated guide rollers 5, 24 and 25 and a feed-out roller 6 as shown, these rollers being mounted on respective shafts 5a, 24a, 25a and 6a, respectively, which are'mounted in turn through respective bearings on the front and rear panels of the casing 1, although not shown only for simplicity of the drawing.

One of these guide and feed-out rollers, preferably latter, is formed into a positive drive roller which is mechanically coupled through proper transmission and reduction gearing means to a self-contained electric motor, although not shown by virtue of their very popularity. This motor is connected through proper lead means and said main switch to the current source, although not shown.

A stationary guide table 7 is fixedly mounted on the right-hand wall 1a of casing 1 at 7a and extends horizontally from outside into the interior space thereof towards the engaging point between drum 4 and roller 5 as shown. The casing wall 1a is formed with a reception opening 26 through which the guide table 7 extends inwardly as above referred to. This opening 26 has an ample size for reception of a stack of a negative 27 and a positive stock sheet 28.

In a close proximity to the engaging point between drum 4 and feed-out roller 6, there is provided a channel-sectioned guide member 8 which is mounted on the front and rear panels of casing 1, and fitted at its lefthand end, FIG. 1, with a doctor 9 kept in slidable contact with the rotatable drum 4, the inclination of the doctor being so selected that the fed-out stack of the negative and positive sheets is separated from the drum surface and led to travel along a channel-shape passage substantially corresponding to the sectional configuration as shown, of guide member 8.

Directly above the delivery end of the guide member 8, there is provided a differential feed mechanism 10 comprising a pair of mutually engaging feed rollers 10a and 10b having respective shafts 10a and 10b which are rotatably mounted through proper bearing means, not shown, on the front and rear panels of casing 1 as before. These rollers are of the positively driven type, although the mechanical transmission means from the drive motor have been omitted only for simplicity of the drawing. It should be noted, however, that the rotational speed of second roller 10b is substantially higher than that of the cooperating first roller 10a, for instance, at a relative ratio of 2:1, as hinted by doubleheaded arrow X attached to the second roller in comparison with a single headed arrow Y allocated to first roller 10a.

At a higher lever than the differential feed mechanism 10, there is provided an automatic separator mechanism proper as shown generally at 11, which comprises a positively driven roller 12, although the mechanical connection thereof to the power transmission means of the photo-copier has been omitted from the drawing for simplicity. The shaft 12a is rotatably mounted through proper bearings on the front and rear panels of casing 1 as before. A leaf-shaped guide element 14 is kept in slidable contact with the upper part of the peripheral surface of the drive roller 12, and mounted pivotably at its root end by means of a pivotable mount 13 mounted in turn on the rear panel 1c of casing l, as shown. A weight mass 15, preferably shaped into a lateral bar as shown, is mounted at a proximity of the free end of the guide member 14. This weight mass 15 is slidable along a guide groove 15a of a stationary guide piece 15a fixedly attached to the rear panel 1c. In this way, the member 14 is kept in pressure contact with the roller 12. The drive roller 12 is designed and arranged to rotate at a slower speed than the faster one 10b of the differential feed mechanism 10. It should be noted the materials of these cooperating element 12 and 14 are so selected that the frictional coefficient between the roller 12 and the positive sheet 28 is larger than that between the guide member 14 and the sheet 28.

At an intermediate level in the machine between the both mechanisms 10 and 11, there is provided a stationary guide plate 16 which is inclined at an angle beta with the horizontal, as is most clearly seen from FIG. 3, and fixedly mounted at 16a on the rear panel 10, as shown in FIG. 1.

The developing section 2 comprises a positively driven developing roller 17, although the mechanical connection thereof with the built-in drive means have been omitted from the drawing only for simplicity. This roller 17 cooperates with an applicator roller 29 which is dipped partially in a developing bath 30 contained in a stationary container vessel 19 supported by the casing 1, although the supporting means have been omitted from the drawing by virtue of their very familiar nature. A feed-out roller 18 is arranged to cooperate through belt 23 with guide roller 25, so as to feed the positive sheet 28 from the mechanism 11 to the developing section 2, as will be more fully described hereinafter. The side wall lb of easing l is formed with a feed-out opening 20 in proximity to the developing section 2.

Rollers 17, 18, and 29 are rotatably mounted at their respective ends on the front and rear panels of the casing 1 as before.

The operation of the photo-copier so far shown and described is as follows.

At first, the main switch, not shown, is switched on, so as to bring the positively driveb and follower mem bers 4, 5, 6, 10a, 10b, 17, 18, 23, 24, 25, and 29 into actuation. The lamps 21 and 22 are also ignited.

Under these ready-for-operational conditions of the photo-copier, a stack of negative and positive sheets 27,28 is introduced through inlet opening 26 and along the table 7 into the interior space of the machine casing 1. The elongated stack. is then fed to the cooperating point between drum 4 and roller 5 through belt 23; and led to travel along with the outer peripheral surface of the now rotating drum 4 and fed out through the engaging point between drum 4 and roller 6 through the belt, upon having been exposured by light beams from the stationary light source 21;22. Then, the stack is guided along the channel-shaped guide passage defined by guide member 8 and fed to the engaging point of the differential rollers 10a and 10b.

During passing through the differential feed mechanism 10, the positive sheet 28 is fed substantially faster than the negative sheet 27 and under such differential feed conditions, the both sheets are guided along the guide plate 16, thus the leading edge of the former advancing several millimeters or even several centimeters than that of the latter, as may be easily thought out from the foregoing and by reference to FIG. 1 until they pinge upon the leaf member 14 for performing the desired separation job. This job can be easily understood by observing FIGS. 2-4, especially the latter in which several steps for the separation are clearly demonstrated.

As seen especially from the final stage (4) of FIG. 4, the positive sheet 28 which is generally more rigid than the negative sheet 27 will bulge out outwardly upon having impinged upon the leaf member 14, so as to drive out the drailingly arriving leading edge of the negative which thus, generally speaking in practice, does not contact with the member 14. The leading edge of the bulged-out leading portion which has been effectively separated from the negative in the aforementioned way, will advance along the lower surface of said member 14, until it is caught by the cooperating roller 12 with the latter, thence further fed, upon guided by a stationary guide member 31 towards the feed-out roller .pair 18 and 25 cooperating through the belt 23 with each other.

The aforementioned bulge-out of the positive sheet 28 is caused by the speed differential between rollers 10b and 12. The thus separated negative sheet 27 is delivered through an outlet opening 32 formed through casing wall 1a, and accumulated in a receptacle 33 which is rigidly supported by the same casing wall.

The fed-out positive sheet 23 from the roller pair 18;25 is subjected to a development at the section 2 as conventionally, and finally delivered from outlet opening 20 into a receptacle 34.

It should be mentioned that for attaining the purpose of the invention, the frictional coefficient between drive roller 12 and positive sheet 28 must be substantially larger than that acting between guide plate 14 and the sheet 28. If not, a successfull feed of the positive sheet upon separation to the engaging point between roller 12 and guide 14 could not be realized.

Optimum relative conditions among the members 12-15 may be calculated as follows:

Now, it is assumed that the guide plate 11 is inclined at angle of alpha with the horizontal, and the distances L, 1W and IR are selected as shown in FIG. 3. Further, that the weight mass has a mass: W; and guide plate 16 has an included angle beta with the horizontal.

Then, the pressure acting upon the drive roller 12 will be:

By assuming a proper and general nature of the positive paper stock, the related parts canwell be designed easily, for satisfying the above formula.

In the following, proper design conditions of the related parts and selected material therefor will be mentioned for better understanding of the invention.

The drive roller 12 is made of chloroprene sponge and fixedly mounted on the shaft 12a made of regular soft steel. As the fixing means therebetween, conventional adhesive was used. The outside diameter of the roller 12 was l8 mm and the peripheral surface thereof was carefully polished. The hardness was measured to 25 Rockwell hardness C.

As material the guide plate 14, quenched hard steel was used and the thickness amounted to 0.15 mm. The acting surface of the plate 14 was coated with a film of fluorine resin, 0.3 mm thick, and included with finely divided glass powder. The adhesive was of the epoxy resin base. The differential rollers 10a and 10b were so designed to provide a longitudinal off-phase between the sheets 27 and 28 amounted to at least mm.

When the width of the positive amounted to 480 mm, then:

1w IR 57 mm; 51 mm;

L 12 mm; A 10 cm; W 385 g; alpha 52 deg; beta 71 deg;

the operation was successfully carried out over the mean travel speed of the sheet stack amounting to 30-450 m/hr.

In the modification shown at 11 in FIG. 5, the weight mass 15 has been dispensed with and instead, the guide plate 14 is subjected to a spring force provided by a spring 100 tensioned between a stationary post 101 on rear housing panel 1c and an arm 102.

which fixedly attached to the guide plate 14 at its root portion.

The guide plate 14 must not always be straight. In the modification shown in FIG. 6, the plate at 14" has a wavy form. In this modification 11", an arm constructed in the similar way as that shown at 102 in FIG. 5 is arranged to coact with a stationary stop pin 103 provided on the panel 10.

The term positive sheet as used throughout the specification denotes a photo-sensetive sheet, coated for instance, with an aqueous solution of conventional Diazo compound, while the negative sheet includes a transparent or semi-transparent original sheet.

By selecting the sum of inclination angles Alpha and Beta in the foregoing, the creation of the bulgeout portion by the positive sheet upon collision of the leading edge thereof against the plate 14 will be highly accentuated. By selecting the rotational speed of drive roller 12 to be appreciably smaller than that of the faster differential feed roller 10b, the bulge formation by the positive can be correspondingly accentuated. Upon such gradually increasing bulge-out formation by the positive, the negative will be pushed out forcibly and physically outwards.

The inclination angle of the guide plate 14 should preferably be measured at the intersecting point of an extension of first guide plate 16 with the second guide plate 16 with the second guide plate 14, especially when the latter should take a curved configuration, especially along the range defined by and between the engaging point between roller 12 and plate 14 and the ourward tip end of the latter, because the conditions and the inclination angle at the said intersecting point will play an important role for the creation of said bulged shape.

What is claimed is:

l. A photo-copying machine comprising in combination: a stationary box-shaped casing, exposure means having an output portion provided therein, developing means having an inlet portion mounted within said casing, means defining an elongated and curved passage route extending from the output portion of said expo sure means to the inlet portion of said developing means for guiding a positive sheet wholly therealong and a stack consisting of said sheet and a negative sheet partially therealong, an automatic separating mechanism provided at an intermediate point along said passage route for separating said stack into said negative and positive sheets, a differential feed roller pair provided at. an intermediate point along said passage route and between said exposure means and said separating mechanism, a first guide plate positioned at an intermediate point along said passage route and between said differential feed roller pair and said automatic separating mechanism, said plate being inclined at a first angle with the horizontal and having a surface against which the positive sheet contacts, said separating mechanism comprising a rotatable resilient roller and a second guide plate cooperating therewith, said second guide plate being inclined at a second angle with the horizontal and having a lower surface in a plane which intersects and extends beyond the plane in which the surface of said first plate lies, said differential roller pair consisting of a slower speed roller and a faster speed roller cooperating therewith and providing a substantial speed difference therebetween, so as to create a traveling lag of the negative in comparison with the positive, the sum of said first and second inclination angles being larger than and the rotational speed of the said faster feed roller being higher than that of said resilient roller, thereby forming a gradually increasing and outwardly directing bulge upon collision of the leading edge of the leading positive sheet against the said second guide plate for forcibly and physically pushing the lagging negative sheet outwardly to separate said sheets. 

1. A photo-copying machine comprising in combination: a stationary box-shaped casing, exposure means having an output portion provided therein, developing means having an inlet portion mounted within said casing, means defining an elongated and curved passage route extending from the output portion of said exposure means to the inlet portion of said developing means for guiding a positive sheet wholly therealong and a stack consisting of said sheet and a negative sheet partially therealong, an automatic separating mechanism provided at an intermediate point along said passage route for separating said stack into said negative and positive sheets, a differential feed roller pair provided at an intermediate point along said passage route and between said exposure means and said separating mechanism, a first guide plate positioned at an intermediate point along said passage route and between said differential feed roller pair and said automatic separating mechanism, said plate being inclined at a first angle with the horizontal and having a surface against which the positive sheet contacts, said separating mechanism comprising a rotatable resilient roller and a second guide plate cooperating therewith, said second guide plate being inclined at a second angle with the horizontal and having a lower surface in a plane which intersects and extends beyond the plane in which the surface of said first plate lies, said differential roller pair consisting of a slower speed roller and a faster speed roller cooperating therewith and providing a substantial speed difference therebetween, so as to create a traveling lag of the negative in comparison with the positive, the sum of said first and second inclination angles being larger than 90* and the rotational speed of the said faster feed roller being higher than that of said resilient roller, thereby forming a gradually increasing and outwardly directing bulge upon collision of the leading edge of the leading positive sheet against the said second guide plate for forcibly and physically pushing the lagging negative sheet outwardly to separate said sheets. 